Top 10 Rich Countries in the World

America is ...... richest country in the world.

How many megadiversity countries are there in the world ?

Which among the following ranked 5^(th) on the list of 'Top 10 Landmarks' in the world by TripAdvisor Travellers' choice Awards?

What are the common bases of classification of urban settlements of the world? Why is the number of cities increasing at a fast rate in the developing countries of the world ?

The World Bank, an international financial institution, provides loans to countries of the world for capital projects. Where is it Headquartered?